Hydraulic power units serve as power supplies for hydraulic tools, and generate a flow of hydraulic fluid utilized to power such tools. Typically, some hydraulic power units contain an internal combustion engine, a hydraulic pump (e.g., a gear pump), and similar assemblies which provide output of hydraulic fluid (e.g., hydraulic oil) through hoses that may be coupled to hydraulic tools to power those tools.
In some conventional hydraulic power units, a power take-off (PTO) shaft associated with the internal combustion engine may drive a fan, such as a squirrel cage fan, to draw air from outside of the hydraulic power unit. The air may be utilized to pressurize the volute, and be utilized in an air-to-oil intercooler to cool the hydraulic circuit from the heat generated by the hydraulic tools. It may be appreciated that some conventional hydraulic power units, such as that marketed as the Stanley GT18, may be configured so that an air flow to the air-to-oil intercooler may be drawn from outside of the power unit (e.g., ambient air), which may be cooler than air drawn across the engine, or been recirculated from engine cooling air or exhaust air, as utilized in other conventional embodiments.
Among other things, the present application relates to an improved hydraulic power unit design, including being configured with improved air flow to an air-to-oil intercooler, and improved arrangement of the constituent components.